IoT devices are physical objects that may communicate on a network, and may include sensors, actuators, and other input/output components, such as to collect data or perform actions from a real world environment. For example, IoT devices may include low-powered devices that are embedded or attached to everyday things, such as buildings, vehicles, packages, etc., to provide an additional level of artificial sensory perception of those things. Recently, IoT devices have become more popular and thus applications using these devices have proliferated.
Wireless sensor networks (WSN) have many IoT applications that measure spatially-distributed sparse sensor fields (e.g., temperature, pressure, humidity, etc.). For example, WSNs in cold chain logistics enable real-time monitoring of sparse temperature fields ranging from several weeks to months. In particular, spatial WSNs in a mesh (e.g., a tree) topology are scalable to large network sizes with greater coverage. Techniques traditionally used to calculate the best routing schedule suffer from limitations, such as having data throughput that rises sharply in relay nodes that are closest to a gateway causing severe load balancing problems, or requiring all nodes in the network participate in the data gathering process, which causes high network power consumption, especially when the sensor field is sparse.